The present invention relates generally to excavation apparatus, and more particularly provides a uniquely configured excavating tooth and wear cap assembly for installation on an excavating bucket, dipper or the like.
Large excavating buckets, dippers or the like are typically provided with a series of earth-cutting teeth which are each formed from two primary parts--a relatively large adapter and a relatively small replaceable point. The adapter has a base portion which is connectable to the forward lower lip of the bucket and a nose portion onto which the tooth point is removably secured by a suitable connecting pin. Compared to that of the adapter, the useful life of the point is rather short--the adapter typically lasting through five or more point replacements until the tremendous earth forces and abrasion to which it is subjected necessitates its replacement.
Since the much larger adapter is considerably more expensive than its replaceable point, efforts have been made to further prolong its life by providing it with a variety of externally mounted wear cap or plate structures which function to shield the external surface of its base portion from abrasion. When the wear cap becomes sufficiently worn it is simply replaced to thereby significantly extend the useful life of the adapter.
While a variety of known wear cap structures do indeed extend the lives of the adapters which they shield, they have heretofore created another problem in the tooth assembly which, to a substantial extent, offsets their usefulness. Specifically, the various methods previously used to connect conventional wear caps to tooth adapters permit the caps to be driven by forwardly directed earth forces into the point, thereby deforming the pointadapter connecting pin. Such deformation can render point removal extremely difficult and often necessitates premature removal and replacement of the entire tooth assembly.
Another problem associated with conventional wear caps is that they can be rather awkward and difficult to field-install on the adapter base. This is particularly true relative to wear caps which are installed on the downwardly facing surface of an adapter base and partially retained in place by the subsequently installed replaceable point. Typically, such lower wear cap (a relatively heavy structure) must be hand-held against the adapter base while the point is being slipped onto the adapter nose. Because the point is also usually quite heavy this is commonly a two-man project - one man slipping the point onto the adapter nose while another man is holding the lower wear cap temporarily in place.
In view of the foregoing it is an object of the present invention to provide an improved excavating tooth and wear cap assembly which eliminates or substantially minimizes above-mentioned and other problems and disadvantages associated with conventional tooth and wear cap assemblies.